As disclosed in JP 2004-232498 A, an in-vehicle control apparatus stores, in a backup storage, analysis data utilized in an analysis of an abnormality occurred to a vehicle.
The in-vehicle control apparatus disclosed in JP 2004-232498 A includes a central processing unit (CPU), a random access memory (RAM), a backup RAM. The backup RAM functions as the backup storage. The control apparatus is connected with various sensors. The CPU acquires various respective detection data from the various sensors, and temporarily stores the detection data in the RAM. The CPU executes a self-diagnostic process in order to detect an abnormality occurred to the vehicle.
The various detection data temporarily stored in the RAM are treated as data necessary to be backed up. Thus, the various detection data temporarily stored in the RAM are stored in the backup RAM at predetermined time intervals. That is, the various detection data temporarily stored in the RAM are backed up in the backup RAM at predetermined time intervals. The control apparatus divides the various detection data stored in the RAM into several data groups based on a changing amount of each detection data with respect to time. Then, the control apparatus stores each data group in the backup RAM at predetermined time intervals. The predetermined time interval is set for each data group.
The control apparatus stores each data group in a first storing section of the backup RAM at the predetermined time intervals set for each data group before an abnormality is detected by the self-diagnostic process. When an abnormality occurrence is detected by the self-diagnostic process, the control apparatus stores each data group in a second storing section of the backup RAM. Then, the control apparatus stores each data group in a third storing section of the backup RAM at the predetermined time intervals set for each data group.
As another example different from the configuration disclosed in JP 2004-232498 A, an in-vehicle control apparatus may be connected to a different in-vehicle apparatus, which performs a self-diagnostic process based on detected vehicle signals and outputs the detected vehicle signals to the in-vehicle control apparatus. In this configuration, the in-vehicle control apparatus acquires, from the different in-vehicle apparatus, detection data that includes vehicle signals and diagnostic result of the self-diagnostic process. Thus, the in-vehicle control apparatus need not necessarily perform the self-diagnostic process. When the detection data acquired from the different in-vehicle apparatus includes the diagnostic result indicating an occurrence of the abnormality, the in-vehicle control apparatus may store, in a backup storage, the vehicle signals included in the detection data as the analysis data to be utilized in an analysis of an abnormality reason.
Usually, vehicle signals acquired at an appearance time of an abnormal symptom is effective and useful for an analysis of the abnormality reason. The above-described in-vehicle control apparatus may fail to store the effective and useful data for analyzing the abnormality reason in the backup storage.